Intravascular persistence

Solution Mean MW (kDa) Volume expansion (%) Intravascular persistence (h)... 

Fluosol s shortcomings included prolonged organ retention of F-tripropylamine (reticuloendothelial system (RES) half-life 65 days), complement activation, and hemodynamic effects due to Pluronic, excessive dilution, limited intravascular persistence, insufficient stability, and lack of user-friendliness. The product came as three separate preparations the frozen stem emulsion and two annex salt solutions. The stem emulsion had to be carefully thawed, then admixed sequentially to the annex solutions, and the reconstituted product had to be used within 8 h. This cumbersome procedure, the short window for use, the further need for administering a small-test dose to patients prior to infusion in order to identify those patients who were sensitive to Pluronic, contributed to compromising the product s commercial success. 

Thompson W L, Fukushima T, Rutherford R B et al 1970 Intravascular persistence, tissue storage, and excretion of hydroxyethyl starch. Surgery, Gynecology and Obstetrics 131 965-972... 

The clinical applications of HES have been reviewed by Lutz (1975) and Thompson (1978). For particular pharmacologic and biologic effects of HES see the following literature hemostasis and coagulation (Alexander 1978), intravascular persistence in humans (Thompson et al. 1970 Boon et al. 1976), and storage in animals (Lindblad and Falk 1976). 

Arturson G, Wallenius G (1964) The intravascular persistence of dextran fractions of different molecular size in normal humans. Scand J Clin Lab Invest 1 76-80 Aspinall GO (1970) Polysaccharides. Pergamon, Oxford Bach J-F (1976) Immunologic. Flammarion, Paris... 

Boon JC, Jesch F, Ring J, Messmer K (1976) Intravascular persistence of hydroxyethyl-starch in man. Eur Surg Res 8 497-503... 

Thompson WL, Britton JJ, Walton RP (1962) Persistence of starch derivatives and dextran when infused after hemorrhage. J Pharmacol Exp Ther 127 39-45 Thompson WL, Wayt DH, Walton RP (1964) Bleeding volume indices of hydroxyethyl-starch, dextran, blood, and glucose. Proc Soc Exp Biol Med 115 474-477 Thompson WL, Fukushima T, Rutherford RB, Walton RP (1970) Intravascular persistence, tissue storage and excretion of hydroxyethylstarch. Surg, Gynecol Obstet 131 965-972... 

The intravascular persistence of perfluorotributylamine in blood has been measured by F-NMR (nuclear magnetic resonance as well [73]. The detection limit of lO" can be reached with F-NMR Fourier transform spectrometry. 

The intravascular persistence of fluorocarbon emulsions needs to be improved further. The dose-dependent half-life of recent fluorocarbon emulsions is typically 4-12 h [161]. This is sufficient only for surgical procedures, but it is inadequate for cases of trauma and much too short for chronic anemia [161]. 

Persistence of fever beyond 1 week may indicate ineffective antimicrobial therapy, emboli, infections of intravascular catheters, or drug reactions. In some patients, low-grade fever may persist even with appropriate antimicrobial therapy. 

RF catheter ablation is complicated by thromboembolism in about 0.6% of patients (23). The risk of stroke from RF ablation may be higher in paroxysmal AF patients with prior TIA (24). As reflected by elevated plasma D-dimer levels, RF ablation has a thrombogenic effect that persists through the first 48 hours after the procedure (25). Activation of the coagulation cascade in RF ablation procedures is not related to the delivery of RF energy, but is related to the placement of intravascular catheters and to the duration of the ablation procedure (26,27). Furthermore, RF lesions themselves have been shown to be thrombogenic (28). The risk of a thromboembolic complication is higher for left-sided ablations... 

Mineralocorticoid excess also plays a significant role in the maintenance of metabolic alkalosis. In patients with volume-responsive metabolic alkalosis, intravascular volume depletion stimulates aldosterone secretion. As discussed earlier, excess mineralocorticoid activity may also underlie the generation of metabolic alkalosis. In either situation, the increased mineralocorticoid effect stimulates collecting duct H+ secretion. Metabolic alkalosis may also be maintained by persistent hypokalemia. Hypokalemia has a multitude of effects on renal acid-base homeostasis, enhancing proximal tubular bicarbonate reabsorption, stimulating ammoniagenesis and increasing distal tubular H secretion. ... 

Many clinicians advocate early institution of empirical TV amphotericin B in patients with neutropenia and persistent (>5-7 days) fever. However, the potential toxicities (particularly nephrotoxicity) of this agent preclude its routine use in all patients. Suggested criteria for the empirical use of amphotericin B include (1) fever of 5 to 7 days duration that is umesponsive to antibacterial agents, (2) neutropenia of more than 7 days duration, (3) no other obvious cause for fever, (4) progressive debilitation, (5) chronic adrenal corticosteroid therapy, and (6) indwelling intravascular catheters. In patients who fail therapy with amphotericin B, hpid formulations of amphotericin B may be used (3-5 mg/kg per day). 

One of the most serious types of infection occurs when the blood clot biofilm surrounding the intravascular portion of the cannula becomes microbially colonized, leading to phlebitis, a bloodstream infection that usually persists after the cannula has been removed. This is an extremeiy serious condition, particularly in burn and ICU patients. Before leaving this topic, let us discuss cannula-related infection in more detail. 

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